Contraction Timer Calculator

Frequently Asked Questions

How does the timer measure my contractions?

It records the start and end of each contraction (duration in seconds) and the gap from the start of one to the start of the next (frequency in minutes). It shows a rolling average so you can see if they are getting longer, stronger, and closer.

What is the 5-1-1 rule?

For a first-time labor, many providers say go to the hospital when contractions are 5 minutes apart, lasting 1 minute each, for at least 1 hour straight. The tool flags when your rolling pattern hits 5-1-1 (some practices use 4-1-1).

How do real labor contractions differ from Braxton-Hicks?

Braxton-Hicks are irregular, often painless, and ease with hydration or position change. True labor contractions get progressively longer, stronger, and closer together regardless of activity, and typically wrap from back to front.

When should I call my provider before 5-1-1?

Call right away for water breaking, bleeding heavier than spotting, decreased fetal movement, severe pain, or contractions before 37 weeks. Always follow your OB-GYN's personal instructions - this timer is informational, not medical advice.

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Pregnancy & Baby Disclaimer: Educational only. Not medical advice.

This calculator is for general informational and educational purposes only and is not medical advice. It does not diagnose, treat, prevent, or replace care from your OB-GYN, midwife, pediatrician, or other qualified healthcare provider. Always consult your healthcare provider for any decisions about your pregnancy, your baby, or your postpartum recovery.

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How This Calculator Works

Labor timing is built around two numbers: how long each contraction lasts (its duration, measured from start to end), and how often they come (their frequency, measured from the start of one contraction to the start of the next). Tap Start when a contraction begins and End when it lets go; the timer captures both timestamps. Over your most recent six contractions the tool reports the average duration in seconds, the average start-to-start interval in minutes, and whether you have crossed the widely-taught 5−1−1 threshold for first-time labor - contractions every 5 minutes, lasting 1 minute each, for at least 1 hour. For subsequent labors many providers use 7−1−1 or simply “come in when contractions are regular and strong.”

Formula / Method

Duration_i = end_i − start_i; interval_i = start_i − start_i−1. Averages are taken over the last 6 contractions to filter out a single outlier. The 5−1−1 flag fires when average interval ≤ 5 min, average duration ≥ 60 s, and at least 6 contractions have been logged (a proxy for the “for an hour” condition; at 5-minute spacing, six contractions span about 25 minutes - widen the sample if your provider asked for a full hour). Note that early labor often presents as irregular contractions of varying length and gap (Braxton Hicks, prelabor); timing them is useful precisely so you can tell when the pattern changes to the regular crescendo of active labor.

Worked Example

You start timing at 9:00 PM. Contractions begin at 9:00, 9:09, 9:18, 9:27 (durations 45, 50, 55, 60 s). Average interval = 9.0 min, average duration = 52.5 s - not yet 5−1−1, consistent with early labor. By 11:30 PM your last six contractions started at 10:40, 10:45, 10:50, 10:55, 11:00, 11:05 with durations averaging 65 s. Interval = 5.0 min, duration ≥ 60 s, six in a row - 5−1−1 met. Per most US first-time-labor guidance this is the cue to call your provider or head to the birth setting, unless you have been told something different for your specific situation.

Common Mistakes

Timing interval as end-to-start instead of start-to-start - the correct “every N minutes” figure uses start-to-start.

Confusing Braxton-Hicks (irregular, painless or mild, do not progress) with true labor (regular, intensifying, closer-together) - only true contractions follow the 5−1−1 pattern.

Applying 5−1−1 to subsequent pregnancies - second and later labors often progress faster; many providers advise calling earlier (7−1−1 or at the first regular pattern).

Waiting on the calculator for a clear emergency - water breaking with green/brown fluid, heavy bleeding, severe constant abdominal pain, or markedly decreased fetal movement warrant an immediate call regardless of contraction timing.

Forgetting that the threshold is guidance, not a rule - if you live far from your birth setting or have a high-risk pregnancy, your provider may have given you a different individualized trigger.

Tips & FAQ

What if I lose count? Just tap Start when the next one begins; the rolling six-contraction window auto-updates. Can my partner do the timing? Yes - many people prefer it; the laboring person focuses on breathing and position while the partner times. What about “back labor” or unusual pain locations? Pain location doesn't change the timing rule; duration and frequency still matter. Is one minute too strict for duration? Early labor contractions can be shorter (30–45 s) and still be true labor; the “1 minute” component is part of an established pattern, not a single measurement - if everything else looks like active labor and your contractions are 50 seconds, call anyway. What about contractions that don't hurt? Painless contractions are usually Braxton-Hicks. Painful, regular, intensifying contractions in the last weeks of pregnancy are the labor pattern. This tool is a timing aid, not medical advice - follow the instructions your prenatal provider or birth setting has given you and call them when in doubt.

Contraction Timer Calculator

Frequently Asked Questions

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